$-5lm - 8ln - 9l - 3 = -3m - 5$ Solve for $l$.
Solution: Combine constant terms on the right. $-5lm - 8ln - 9l - {3} = -3m - {5}$ $-5lm - 8ln - 9l = -3m - {2}$ Notice that all the terms on the left-hand side of the equation have $l$ in them. $-5{l}m - 8{l}n - 9{l} = -3m - 2$ Factor out the $l$ ${l} \cdot \left( -5m - 8n - 9 \right) = -3m - 2$ Isolate the $l$ $l \cdot \left( -{5m - 8n - 9} \right) = -3m - 2$ $l = \dfrac{ -3m - 2 }{ -{5m - 8n - 9} }$ We can simplify this by multiplying the top and bottom by $-1$. $l= \dfrac{3m + 2}{5m + 8n + 9}$